1. Field of the Invention
The present invention relates to a flash memory device, and more particularly, a flash memory device where a bank select circuit needs not to be modified even though location of the boot region is changed after completion of a design.
2. Background of the Related Art
A flash memory device being a nonvolatile memory device has a memory cell array where a boot region and a user region are divided. At this time, the boot region is a region for storing system information, which is not allowed to be freely rewritten by a user. The user region is a region that could be freely rewritten by a user.
Data stored at the boot region could be executed by setting a given operating mode by a user. This boot region is located at the start portion or an end portion of the memory cell array, i.e., the top or bottom of the memory cell array. The location of the boot region may be changed depending on circumstances requested by an application. Thus, it is necessary for the developer and designer of the flash memory device to consider the two things. At a time point when development is about to be finished, the start portion or the end portion may be decided, or these portions may be developed as an individual product. For this reason, there is a load that the circuit has to be verified twice. Furthermore, the bank select circuit for controlling the operation of the bank must be modified by selecting the bank depending on the location of the boot region. Meanwhile, a flash memory device in which the boot region is not located only at one place of the top and bottom of the memory cell array but is located both at the top and bottom, has been developed. Therefore, a method of managing the boot region of the three modes is required and bank select circuit has to be modified accordingly. Due to this, there are problems that not only respective circuits must be individually discriminated in designing the flash memory but also time taken to verify the circuits is increased and size of the chip is increased.